expression, godan verb (-gu)
be flushed bright red
Rare idiomatic expression describing a face turning bright red, typically from anger or embarrassment. The phrase is literary and not used in everyday conversation.
彼は怒りで満面朱を注いだ。
His face flushed bright red with anger.
The phrase literally means 'to pour vermilion over one's whole face', using classical imagery. The exact origin is uncertain, but it is a fixed idiomatic expression.